help...need parameters for altec 291-16 drivers

[appo1999]

Building a home theater.... mid-range supplied by 3 altec 291-16 horn drivers on 3 Selenium 56-50 horns....In designing the cross-overs the software asks for the FS, qms, qes, Re, Le, and z. of the 291-16's....my target is a 3 way 2nd order Linkwitz-Riley with a 800hz 1st x-over point..Any info on these parameters would be greatly appreciated

[fpitas]

The driver parameters are influenced strongly by the horn, because of the acoustic loading. Unless someone happens to have measured 291s on that horn in particular, you may have to measure them yourself. Also, horn drivers have multiple impedance peaks and troughs, so your crossover has to deal with those, too.

Frankly, for your project the most straightforward approach is an active crossover with biamping. That way the horn driver impedance isn't as much of an issue.

[Alien_Shore]

The driver parameters are influenced strongly by the horn, because of the acoustic loading. Unless someone happens to have measured 291s on that horn in particular, you may have to measure them yourself. Also, horn drivers have multiple impedance peaks and troughs, so your crossover has to deal with those, too.

Frankly, for your project the most straightforward approach is an active crossover with biamping. That way the horn driver impedance isn't as much of an issue.

Yep. What he said.

To illustrate, here's the impedance plot and T/s params of an Altec small-format driver (802-8G) on the Altec 511B horn:

http://imageshack.us/a/img402/2396/ru14.png